Caster



Nov. 2, 1965 R. J. CHROUST 3,214,785

CASTER Filed March 5, 1964 INVENTOR. Poe/527 J. [Heal/ST A TTOENE Y United States Patent "ice 3,214,785 CASTER Robert J. Chroust, 1599 E. 23rd St., Apt. C, Signal Hill, Calif. Filed Mar. 5, 1964, Ser. No. 349,628 1 Claim. (Cl. 1618) The present invention relates generally to the field of movable supports, and more particularly to an improved caster.

A major object of the invention is to provide an improved caster that permits the object with which it is associated to be moved easily over a hard floor surface, or over one covered with deep pile carpeting in which previously available casters sink to such extent that considerable force must be exerted to move the casters thereover.

Another object of the invention is to furnish a caster of simple and inexpensive construction that is reliable and etficient in operation, and one which will not mar or streak a floor surface with which it comes into rolling contact.

Yet another object of the invention is to furnish a caster that can be fabricated from standard commercially available materials, requires no elaborate plant facilities for the production thereof, and can accordingly, be retailed at a sufficiently reasonable price to encourage the widespread acceptance thereof.

These and other objects and advantages of the invention will become apparent from the following description thereof, and from the accompanying drawing illustrating the same, in which:

FIGURE 1 is a perspective view of a rectangular body that is movably supported by four of the casters of the present invention;

FIGURE 2 is an exploded perspective view of one of the devices;

FIGURE 3 is a combined front elevational and vertical cross-sectional view of a first form of caster before it is subjected to a substantial load;

FIGURE 4 is the same view of the device shown in FIGURE 3, but after it has been subjected to a substantially heavy load; and

FIGURE 5 is a combined front elevational and vertical cross-sectional view of a second form of the caster.

With continued reference to the drawing, and to FIG- URES 1-4 thereof for the general arrangement of the first form of caster, it will be seen that a rectangular body A is provided that may be a piece of furniture, baby carriage, or the like, which may be supported by four of the casters B mounted in balanced positions thereon.

Each of the casters B, as may best be seen in FIGURE 2, includes a pintle and a yoke 12, which depends from the lower end of the pintle. Yoke 12 is preferably semicircular, but other shapes such as an inverted rectangular U, or the like, may be employed if desired. Two coaxially aligned, laterally spaced stub shafts 14 extend inwardly towards one another from the lower ends of yoke 12. Each of the shafts 14 is of circular transverse cross section.

Two generally cylindrical members C are provided that are formed from a hard, rigid material such as a polymerized resin, or the like. Each member C has a cylindrical side wall 16, fiat outer end 18, and a pointed inner end 20, as best shown in FIGURE 3. A centrally disposed recess 22 extends inwardly, lengthwise, from the outer end 18 of each member C, which recesses serve to rotatably support the members on the stub shafts 14. Each recess 22 has a ball bearing 24 disposed therein that is situated between the inner extremity of one of the stub shafts 14 and the inner end of the recess engaged by that particular shaft.

3,214,785 Patented Nov. 2, 1965 A rollable body D, which is preferably spherical and can be a ball defined by a tough skin 26 is provided that is fabricated from a polymerized resin, which is inflated with gas or air under pressure. The horizontal external diameter 28 of body D is substantially greater than the lateral distance between the pointed ends 20 the members C, when the members are rotatably supported on the shafts 14, as illustrated in FIGURE 3. When the members C press against body D, two diametrically opposed recessed portions 30 are formed in the body that are engaged by the pointed ends 20 of members C. When the body D is engaged by members C and no appreciable load is imposed on the body, it assumes the configuration shown in FIGURE 3.

However, when a load is imposed on the yoke 12, the load is transferred through the shafts 14 and members C to the rollable body D. When the load is imposed on the skin 26 through the recessed portions 30, that part of the skin 26:: below the members C expands laterally (FIG URE 4) whereby a substantialy flat under portion 26b thereof is in contact with a floor surface 32. When body D is so loaded, it deforms to the extent that the vertical distance between the horizontal center line 34 and the floor surface 32 is less than the vertical distance from the center of the center line 34 and the upper extremity 260 of skin 26.

The pointed ends 22 of members C pressure contact the recessed portions 30 with sufficient force that the members and body D rotate concurrently on the shafts 14. As the rollable body D rotates, sequential circumferential sections thereof are deformed by the load imposed thereon to assume the shape of the skin portions 26a and 26b illustrated in FIGURE 4. The skin portions 26a extend downwardly and outwardly relative to the recessed portions 30, and as a result there is no tendency for the pointed ends 20 to become disengaged from the pointed ends 20 of the members C.

The pointed ends 20 are sufliciently blunt that they will not penetrate the skin 26 of recessed portions 30 when the yoke 12 is subjected to the maximiun load it must sustain. In FIGURE 4 it will be particularly noted that the bottom skin portion 26b is flat, and of sufiicient area that the caster B can be pushed across a soft thick carpet without difficulty. Each of the balls 24 serves as a thrust bearing, if the casters B are subjected to sidewise as well as rearward or forward motion.

A second form of the invention is shown in FIGURE 5 which is identical to the first form thereof, except that the rollable body D is filled with a resilient material such as foamed plastic or rubber 36 rather than air or gas under pressure. Elements comprising the second form of the invention common to elements of the first form thereof are identified in FIGURE 5 by the same letters and numerals used in the first form, but to which a prime has been added.

The pintles 10 and 10 serve to mount the casters B and B on a body A when inserted in an upwardly extending opening formed therein (not shown) as is convention in the mounting of casters on a desired object.

Casters of the structure previously described are used in a conventional manner, which use need not be described.

The rollable body D is preferably a sphere defined by a resilient skin 26. The interior of the body D is preferably filled with a fluid under pressure, which may be air, gas or like material. Two opposite sides of the body D are engaged by the members C in recessed portions 30, as best seen in FIGURE 3. When the body D is loaded, the lower portion thereof deforms in the manner shown at 265 in FIGURE 4 to engage the floor surface 32. Due to the increased area of the portion 2612, over the area 3 of the body D in contact with the floor surface (FIGURE 3), the body D may be easily rolled on a deep heavy carpet, even when carrying a substantial load. Although the body D deforms substantially when subjected to a load, there is no tendency for the members C to move from recesses 30 as the body rotates.

Although the present invention is fully capable of achieving the objects and providing the advantages hereinbefore mentioned, it is to be understood that it is merely illustrative of the presently preferred embodiments thereof and I do not mean to be limited to the details of construction herein shown and described, other than as defined in the appended claim.

I claim:

In combination with a caster that includes a pintle, an inverted yoke depending from the lower end of said pintle, andtwo stub shafts which project inwardly from the lower ends of said yoke, comprising:

(a) two generally cylindrical members having inwardly extending pointed ends and recesses which extend inwardly from the outer ends of said members that rotatably engage said shafts, which members are rotatably supported on said shafts with said pointed ends facing one another and separated by a predetermined distance;

(b) a hollow spherical body defined by a resilient skin that encloses a fluid under pressure, with the diameter of said body being substantially greater than that of said predetermined distance, which body is disposed between said members and has diametrically opposed recesses formed in said skin by pressure contact with 5 said pointed ends of said members, with said body when in pressure contact with said members retaining a generally spherical shape until a downwardly directed load, is applied thereto whereupon the lower portion of said body deforms to increase the area 10 of said body in contact with the surface on which said body rests;

(0) two rigid balls disposed in said recesses between the inner ends of said shafts, which balls serve as 15 thrust bearings when said members are in pressure contact with said body.

References Cited by the Examiner UNITED STATES PATENTS D. 32,224 2/00 Clark et al. 16 21 2,404,269 7/46 Bennett 301-1 3,112,175 12/63 Altorfer 152157 25 ALBERT H. KAMPE, Primary Examiner.

DONLEY J. STOCKING, JOSEPH D. SEERS,

Examiners. 

